Written by Dr. Caledonia Buckheit
If you have a history of genital herpes and you’re pregnant, it’s completely normal to wonder whether herpes could affect your baby. If you’ve recently been diagnosed with genital herpes, you may also have questions about what it could mean for a future pregnancy.
I frequently get these kinds of questions in my office, and the honest answer is: yes, there is a real risk, but it is a manageable one. The vast majority of moms with herpes go on to deliver perfectly healthy babies, unaffected by herpes. What’s most important is knowing your history, communicating openly with your provider, and having a plan.
Here’s what you need to know about genital herpes and pregnancy.
What Is Genital Herpes?
Genital herpes is a common sexually transmitted infection (STI) caused by the herpes simplex virus (HSV). Genital herpes is most often caused by HSV-2, although HSV-1 (the same virus that causes cold sores) is commonly responsible for genital infections as well.
Because the virus hides in nearby nerve roots, it typically sticks around lifelong once an infection has occurred, and recurrence (aka “outbreaks”) is variable. According to the CDC, roughly 1 in 6 Americans between the ages of 14 and 49 has genital herpes. Many people carry the virus and have no idea, either because they’ve never had a recognizable outbreak or their symptoms were mild enough to dismiss as something else. This is important context, because it means your diagnosis is a common one, and nothing to be ashamed of. It also means that the care and strategies around pregnancy and delivery are well-established.
Can Genital Herpes Be Passed to a Baby?
Yes. Genital herpes can be passed from a pregnant person to their baby, most commonly during labor and delivery.
Neonatal herpes (a herpes infection in a newborn) is almost always acquired during delivery. If a baby passes through the birth canal and comes into contact with the virus, infection can occur. Transmission is most likely when there are active genital lesions or, less commonly, asymptomatic viral shedding from the mother’s genitals at the time of delivery.
In rare cases, it can also be transmitted through the placenta or, after delivery, through contact with an active cold sore (HSV-1) from a caregiver.
This is why the timing and circumstances of your infection matter so much.
When Is the Risk of Passing Herpes to a Baby Highest?
Not all herpes histories carry the same risk, and this is probably the most important thing to understand. The risk of neonatal herpes depends largely on whether the infection is new or recurrent.
Primary infection in the third trimester (especially close to delivery)
A new genital herpes infection during the third trimester, particularly close to delivery, carries the highest risk of transmission, somewhere in the range of 25–50%.
When you acquire herpes for the first time during pregnancy, your body hasn’t yet built up the antibodies that would otherwise be crossing the placenta and providing the baby some protection. This is the scenario we are most concerned about.
Recurrent herpes (a long-standing infection that reactivates)
If you have had genital herpes for a long time and experience a recurrence during pregnancy, the risk to your baby is much lower.
The risk of passing a herpes infection to your baby is roughly 1–3% if you have an active outbreak at the time of delivery, and even lower when managed with suppressive antiviral therapy.
No active lesions or prodromal symptoms at delivery
If you have a history of herpes but no signs of an outbreak when labor begins, the risk of transmission is very low.
What Happens If Herpes Is Passed to a Baby?
Neonatal herpes is a serious infection that warrants careful prevention. It can present in three ways:
- Affecting the skin, eyes, and mouth (the least severe form)
- Spreading to the central nervous system
- Causing disseminated infection involving multiple organs.
All forms require prompt antiviral treatment. This is exactly why we take prevention so seriously during pregnancy and delivery.
How Do We Protect Your Baby?
The good news is that there are well-established, effective strategies to minimize risks for baby:
Suppressive antiviral therapy starting at 36 weeks
If you have a known history of genital herpes, we recommend starting a daily antiviral medication (acyclovir or valacyclovir) at 36 weeks of pregnancy. This suppressive therapy reduces the likelihood of an outbreak occurring around the time of delivery, and decreases asymptomatic viral shedding. Both acyclovir and valacyclovir are medications with well-established safety in pregnancy.
Cesarean section if active lesions are present
If you arrive in labor with visible herpes lesions or are experiencing prodromal symptoms (tingling, burning, or itching that signal an outbreak is coming), we will recommend a C-section to avoid exposing the baby to the virus during a vaginal delivery.
Vaginal delivery is generally safe without active lesions
If you have a history of herpes but no active outbreak at the time of labor, a vaginal delivery is considered safe with appropriate precautions.
Tell your provider your full history
If you or your partner has a history of herpes, even if you’ve never had an obvious outbreak, please share that with your obstetric provider early in pregnancy. Knowing your history allows us to test you if needed, monitor appropriately, and start suppressive therapy at the right time.
What If I Don’t Know My Status?
If you’re not sure whether you have herpes and your partner does, or if you’ve had symptoms that were never formally diagnosed, talk to your care team. Blood testing (an IgG antibody test) can determine whether you have been exposed to HSV-1, HSV-2, or both. Knowing your serostatus early in pregnancy can help us counsel you on your specific risk and make a plan.
The Bottom Line
Having genital herpes does not mean you cannot have a safe pregnancy and a healthy baby.
It does mean we need to know about it.
With suppressive antiviral therapy in the third trimester, a clear delivery plan, and open communication with your care team, the risk of passing herpes to your newborn is very low. If you have questions about herpes and pregnancy, please reach out to your Kamm McKenzie doctor or nurse practitioner (https://kmobgyn.com/our-providers/). We’re here to help you navigate this with confidence.
References
1. American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 220: Management of Genital Herpes in Pregnancy. *Obstet Gynecol.* 2020;135(5):e193–e202.
2. Centers for Disease Control and Prevention. Genital Herpes — STI Treatment Guidelines, 2021. https://www.cdc.gov/std/treatment-guidelines/herpes.htm
3. Brown ZA, et al. Effect of serologic status and cesarean delivery on transmission rates of herpes simplex virus from mother to infant. *JAMA.* 2003;289(2):203–209.
4. Corey L, Wald A. Maternal and neonatal herpes simplex virus infections. *N Engl J Med.* 2009;361:1376–1385.
